The mobile communication system has been developed for the user to communicate on the move. With the rapid advance of technologies, the mobile communication system has evolved to the level capable of providing high speed data communication service as well as voice telephony service.
Recently, as one of the next generation mobile communication system, Long Term Evolution (LTE) is on the standardization by the 3rd Generation Partnership Project (3GPP). LTE is a technology designed to provide high speed packet-based communication of up to 100 Mbps and aims at commercial deployment around 2010 timeframe. In order to accomplish the aim, a discussion is being held on several schemes: one scheme for reducing the number of nodes located in a communication path by simplifying a configuration of the network, and another scheme for maximally approximating wireless protocols to wireless channels.
Meanwhile, unlike voice service, the data service is provided on the resource determined according to the data amount to be transmitted and channel condition. Accordingly, the wireless communication system, especially cellular communication, is provided with a scheduler manages transmission resource allocation in consideration of the required resource amount, channel condition, data amount, etc. This is the fact in the LTE system as the next generation mobile communication system, and the scheduler located at the base station (eNB) manages the transmission resource allocation.
Recent studies are focused on the LTE-Advanced (LTE-A) for improving data rate with the adaptation of several new techniques to legacy LTE system. Multimedia Broadcast/Multicast Service one of the techniques to enhanced along with the LTE-A system. MBMS is a broadcast service provided in the LTE system.
Meanwhile, it increases signaling overhead to provide scheduling information on every transmission of data burst for the traffic requiring periodic radio resource allocation such as VoIP. Accordingly, a scheduling technique for providing the user equipment (UE), in advance, with the scheduling information allocating radio resource periodically in order for the UE to transmit data on the radio resource allocated periodically is referred to as Semi-Persistent Scheduling (SPS).
However, there is no clear rule specified how to processing the situation when the downlink subframe having the downlink resource allocated through SPS and the resource for providing MBMS. There is therefore a need of defining operations of the UE clearly.